Problem
By default, the maximum file length on a UnixWare 7 system is
2 gigabytes, but the maximum possible file length supported by
VXFS filesystems on UnixWare 7 systems is 1 terabyte. How do
I enable this large file support on a VXFS filesystem?

NOTE: The maximum supported filesystem size (as opposed to file
size) is 2 terabytes (real filesystem sizes larger than 128
gigabytes have been tested). This support is enabled by default.

Solution
To enable large files support on the root filesystem:

1. Run fsadm to enable the large file support:

# fsadm -Fvxfs -o largefiles /

2. Run fsadm to confirm that the support has been enabled:

# fsadm /

This should report "largefiles".

3. Increase ULIMIT to unlimited:

# ulimit unlimited

4. Ensure SFSZLIM and HFSZLIM are set to "infinity" (which is
represented by 0x7FFFFFFF) and relink the kernel:

NOTE: Increasing SFNOLIM to above 1024 may also cause "netcfg" to take
several minutes to load each component. It is recommended to put
the server into Single User Mode (init 1 or at the boot logo press
space and enter "INITSTATE=S" then press ENTER followed by "go").

NOTE: You can also increase SCORLIM and HCORLIM but you should be aware that
if you application core dumps then the size of the core file will
equal that of memory.

NOTE: It is not recommended to set the file size to unlimited on the root
filesystem in order to ensure that the root file system does not run
of disk space unnecessarily.

NOTE: If you system has large processes that require more memory than the
standard kernel configuration will allow, and therefore you find that
they are slow then increasing SSTKLIM/HSTKLIM and SVMMLIM/HVMMLIM will
adddress this.

SVMMLIM: (max 0x7FFFFFFF) is the soft limit specifying the maximum
address space that can be mapped to a process (HVMMLIM is the hard
limit).

STKLIM: (max 0x7FFFFFFF) is the the maximum stack size for a process
and the process stack resides within the [SH]VMMLIM address space) -
HSTKLIM is the hard limit.

ie. This is 4GB - 1 byte; 32bit architecture.

Therefore, the maximum amount of RAM that one process can consume is
no more than 4GB.